Centrifugal pump



April 1, 1941. R. D. SCHOTT CENTRIFUGAL PUMP Filed Dec. 30, 19258 peller ll, it will be observed that a comparatively large cavity I! is formed in the lower surface of the hub portion of the bowl. In the absence of the impeller, this cavity would be open at the lower surface of the bowl hub but, with the impeller assembled in the bowl, the impeller substantially seals the lower end of the cavity. Preferably, the impeller is formed with an annular recess is in its upper surface which, in effect, constitutes a continuation of the cavity l8, this annular recess being defined at its outer edge by an annular flange. which slidingly telescopes, so to, speak, the annular surface of the cavity in the bowl hub. If desired, a liner ring 2|, preferably of rustless steel, may be secured in the lower edge portion of cavity l8 for engagement with the flange 20 on the impeller. I

Bearing sleeves 22 for the shaft l5 are usually provided in the hub-portion M of each bowl but,

with the present construction, there is a limited clearance between the shaft and its sleeves and the bowl hub portion or at least suiiicient clearto permit fluid to enter the cavity I8. It might be said that the under surface of the impeller is the suction side thereof, while the area above the impeller is the pressure side, as the water above the impeller will, of course, be under pressure. Due to the fact that the water is under pressure, the entry of water through the more or less minute openings around the shaft to the cavity i8 is augmented. As a result, this cavity between the impeller and the hub portion of the bowl becomes filled with water. This cavity is formed essentially in the bowl, although, in the present structure, the recess It in the impeller'lnight be said to constitute an extension thereof. The flange III on the impeller forms substantially a seal with the liner ring 2i and thus the water entering the cavity I8 is trapped therein. Thus, with this body of water confined in. the space between the impeller and bowl, it constitutes a substantially incompressible mass or body and, as a result, the vibratory motion that would ordinarily be set up is absolutely precluded by reasons of the fact that the .impeller cannot move axially toward the hub portion of the bowl. It is not a case of overcoming a vibratory motion once set up. arrangement, the vibratory motion never comes into existence. It is correct to say, with the present construction, the vibratory motion that would otherwise be present is absolutely dampedout. 7

It will be appreciated that the number of associated bowls and impellers may be varied in accordance with the necessities in connection with any particular well and, likewise, that any number of the bowls and their impellers may be formed to provide this incompressible mass be-v tween them. The type of construction illustrated is applicable to all types of impellers including fully enclosed and semi-enclosed impellers for all deep .well pumping of liquids. In a broad sense,

it is contemplated that amaterial, other than the liquid pumped by the pump, may beused With the present j for the incompressible body between the bowl and impeller, but it'is preferred to use the liquid pumped by the pump because there is less likelihood of contamination of the liquid being pumped. The liner ring 2! against which the flange 20 of the impeller has a close. working fit permits ready replacement in the case of undue wear. although the liquid pumped will function as a lubricant to minimize wear at this point.

- With the exception of the provision of the cavity It in the hub portion of the bowl, the bowl may otherwise be of ordinary construction. It might be added that the hub portion of thebowl is supported by any number of webs 23 connecting said hub portion with the outer shell of the bowl.

While a deep well turbine pump has been adapted for purposes of illustrating the present invention, it will be appreciated that the invention is applicable to centrifugal pumps generally, of either the vertical or horizontal type and the appended claims are not to be limited to any specific type of centrifugal pump, except where expressly specified.

What I claim is:

1. A centrifugal pump forwells, having a rotary shaft adapted to be suspended in the well, an impeller fast on said shaft, and a bowl for housing said impeller and having a bearing through which said shaft extends, characterized by said bowl and impeller having a chamber formed between them by an imperforate annular flange on one of .said members telescopically engaging an imperforate annular surface on the other member, said chamber being substantially sealed by said telescoping imperforate surfaoea, and the bearing clearance between said bowl and shaft afiording communication between said chamber and the flow-passage of the pump at a point on the pressure side of the impeller, ,to permit well fluid to pass into and out of said chamber, whereby fluid trapped in the said chamber will form a substantially incompressible mass between the impeller and bowl and resist the tendency of the impeller to move axially toward the bowl under self-induced vibration.

2. A centrifugal pump for wells having a rotary shaft adapted to be suspended in the well, an impeller fixed on said shaft, and a bowl for housing said impeller, characterized by said bowl having a cavity formed therein with the pressure side of the impeller exposed to said cavity, a passage through which welliiuid can flow into and out ofsaid' cavity, said impeller and bowl having imperforate annular surfaces telescopically engaging one another substantially sealing said cavity at all times, except-for said passage, and said passage being restricted whereby fluid trapped in said cavity will .form a substantially RUDOLPH D. SCHOI'I. 

